Energetic efficiency of an agricultural tractor in function of tire inflation pressure

The tire inflation pressure, among other factors, determines the efficiency in which a tractor can exert traction. It was studied the effect of using two tire inflation pressures, 110.4 kPa in the front and rear wheels, 124.2 kPa in the front wheel and 138 kPa in the rear wheels, the energetic efficiency of an agricultural tractor of 147 kW of engine power, in the displacement speed of 6.0 km.h-1, on track with firm surface, with the tractor engine speed of 2000 rpm. For each condition of the tire pressure, the tested tractor was subjected to constant forces in the drawbar of 45 kN and 50 kN, covering 30 meters. It was used a randomized complete block with a 2x2 factorial arrangement (tire pressure and drawbar power) with four replications, totaling 16 experimental units. Data were subjected to analysis of variance, using the Tukey test at 5% probability for comparison averages. The lowest hourly and specific fuel consumption, the lowest slippage of the wheelsets and the highest efficiency in the drawbar was obtained with the tire inflation pressure of 110.4 kPa in the front and rear tires of the tractor, highlighting that lower pressures improve energetic and operational performance of the tractor.

Desenvolvimento e aplicação da instrumentação virtual na unidade móvel de ensaios na barra de tração - UMEB

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Even-sowing pattern strategies for a low-input agricultural system in forage maize

The objective of this study was to verify the effectiveness of new patterns of sowing and to achieve a low-input organic system in two different environments (northern and southern Europe). The study was motivated by the hypothesis that more even sowing patterns (triangular and square) would significantly enhance the growth and yield of forage maize under widely varying conditions, compared with traditional mechanised rectangular seed patterns. An experiment was conducted in Madrid and duplicated in Copenhagen during 2010. A random block design was used with a 2 × 2 factorial arrangement based on two seed-sowing patterns: traditional (rectangular) and new (even) and two weed-management conditions (herbicide use and a low-input system). In both weed-management conditions and locations, the production of aerial maize biomass was greater for the new square seed patterns. In addition, the new pattern showed a greater effectiveness in the control of weeds, both at the initial crop stages (36 and 33% fewer weeds m-2 at the 4- and 8-leaf stages, respectively, in the Copenhagen field experiment) and at the final stage. The final weed biomass for the new pattern was 568 kg ha-1 lower for the Copenhagen experiment and 277 kg ha-1 lower in Madrid field experiments. In the light of these results, the new pattern could potentially reduce the use of herbicides. The results of the experiments support the hypothesis formulated at the beginning of this study that even-sowing patterns would be relatively favourable for the growth and yield of the maize crop. In the near future, new machinery could be used to achieve new seed patterns for the optimisation of biomass yield under low-input systems. This approach is effective because it promotes natural crop-weed competition.

The economics of machinery choice in corn production /

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Effects of borrowing from commercial lenders on farm organization with particular reference to fertilizers, buildings, machinery, livestock, and operating expense /

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Sulfur and its importance in food production, conclusions and recommendations of the Special Subcommittee on Fertilizer and Farm Machinery of the Committee on Agriculture, House of Representatives, based on hearings before the subcommittee February 20-23, 1951.

Mode of access: Internet.

Cyclopedia of applied electricity; a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric light transmission, alternating-current machinery, telegraphy, etc.,

"A compilation of many of the most valuable instruction books of the American school of correspondence."--Forword.

Lincoln on agriculture; address, Wisconsin State Agricultural Society, State fair, Milwaukee, September 30, 1859 ...

"Reprinted from the Proceedings of the society, 1859."

Spreader, sand, towed-type, traction-powered, with wing gate and safety seat, Flink model SS.

"O-222192"--P. [13].

Operator, organizational, direct support, general support, and depot maintenance manual : spreader, aggregate, towed-type, traction powered, highway model R, FSN 3895-436-2835.

"21 June 1973"--Change no. 1.